Algebrahard · Past Paper
If the equation (k-1)x^2 + (k+1)x + (k-1) = 0 has real and equal roots, find k.
A3, 1/3
B3, -3
C1, -1
D2, 1/2
✓ Correct Answer: A — 3, 1/3
D=0 => (k+1)^2 - 4(k-1)^2 = 0. Take square roots: (k+1) = ±2(k-1). Solve for k.
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